.square.correct{
  border-right: var(--square-border-width) solid #339637!important;
  border-left: var(--square-border-width) solid #339637!important;
  border: var(--square-border-width) solid #339637;
  border-radius:6px;
}

.square.incorrect{
  border-radius:6px;
  border-right: var(--square-border-width) solid #f44336!important;
  border-left: var(--square-border-width) solid #f44336!important;
  border: var(--square-border-width) solid #f44336;
}

.square.incorrect>.piece,.square.correct>.piece{
  left:calc(-1 * var(--square-border-width))!important;
  top:calc(-1 * var(--square-border-width))!important;
}